Preliminary data analyses indicate that applying the z-test (Procedure 9.1 on page 388) in Exercises 9.83–9.88 is reasonable.
9.84 Grey-Seal Nursing. The average lactation (nursing) period of all earless seals is 23 days. Grey seals are one of several types of earless seals. The length of time that a female grey seal nurses her pup is studied by S. Twiss et al. in the article “Variation in Female Grey Seal (Halichoerus grypus) Reproductive Performance
At the 5% significance level, do the data provide sufficient evidence to conclude that the
(Note: The sum of the data is 274.9 days.)
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Introductory Statistics (10th Edition)
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